Andrew Lockley and...@andrewlockley.com to me show details 12:22 AM (10 hours ago)
>Do you have a reference for the two thirds? Hi, Andrew - Sure, I guess I should have put in a reference for the assertion. Here's one example: http://www.sciencemag.org/content/326/5953/716 Science 30 October 2009: Vol. 326 no. 5953 pp. 716-718 DOI: 10.1126/science.1174760 REPORT Improved Attribution of Climate Forcing to Emissions Drew T. Shindell*, Greg Faluvegi, Dorothy M. Koch, Gavin A. Schmidt, Nadine Unger and Susanne E. Bauer + Author Affiliations NASA Goddard Institute for Space Studies and Columbia University, New York, NY 10025, USA. *To whom correspondence should be addressed. E-mail: drew.t.shind...@nasa.gov GISS material for the past several years has assumed this - I think the first such paper goes back to @ 2006, actually, but could be wrong on that. I sometimes use a forcing pie chart in climate talks which I got from Al Gore's Our Choice, taken from a Shindell paper, which shows the percentage of +RF respectively as: CO2 43.1% CH4 26.7% BC 11.9% Halocarbons 7.8% CO & VOCs 6.7% N2O 3.8% I thought I read somewhere that it was assumed the IPCC AR5 would reflect this, but I don't know the current state of that.....perhaps Mike would know that..... but nothing would surprise me anymore.... All best, Nathan On Feb 24, 7:57 pm, Nathan Currier <natcurr...@gmail.com> wrote: > Dear Robert, > > You wrote originally looking for help disputing a “skeptic,” and I > hope it hasn’t been > lost upon you that there sometimes seems to be almost as much > disagreement within > the climate community itself as between such “skeptics” and climate > scientists. Indeed, > the outcome of such internal disagreement could eventually be even > more important for our fate > than disputes with those who ultimately have little or no concern for > science whatsoever. > > Perhaps the largest internal struggle in climate science regards > methane. That is why David > Archer recently wrote his strongly titled “Much Ado about Methane,” > which Ken called one of > the best recent pieces on methane emissions. I personally thought it > was one of the most > poorly conceived pieces of climate science from within the climate > community, and the group AMEG – > the Arctic Methane Emergency Group, formed from this Google > geoengineering group – is still > quite concerned with rebutting this piece of writing. I immediately > started my own ongoing > series in response, called Methane in the Twilight Zone, in which I > address Archer’s “Much > Ado” in some detail (particularly in Episode 2), and promptly received > a private note of thanks > from someone at the top of the climate heirarchy at NASA, specifically > for those parts concerning > Daivd Archer’s recent writing. So, you can see that there is, > unfortunately, considerable > disagreement on this! > > The reason, of course, is that methane feedbacks could potentially > upend much of the worldview of > many scientists, and could radically impact this topic of “non- > linearity of climate sensitivity,” as well > as the current state of the climate. You ask about Wasdell’s “ESS,” > and about how it should > impact considerations of geoengineering, but one of the greatest > problems today is that this kind of “high-sensitivity” > view, or any recognition that there could potentially be powerful > tipping points at relatively short time scales, > should impact both geoengineering policy AND emissions policy > (particularly, in terms of advantaging and > prioritizing immediate and large reductions of anthropogenic methane > emissions). > > In terms of other things I noted within your various exchanges, the > best recent work from NASA, now with a > half-decade of pretty robust research behind it, suggests that the > methane forcing is TWO THIRDS of CO2’s > (added RF since industrialization, that is), not one third, as stated > – thus, the recent human methane forcing > is about twice as large as imagined at the time of the IPCC TAR, for > example (exclusive of any earlier impacts > on methane humans might have had). > > Further, in terms of whether there is evidence of increased methane > releases in the arctic, I’ve printed below the > NOAA data from Barrow, Alaska for a given day from the most recent > year available, 2010. Methane spiked to > 2230ppb that day there. The question is really just what and where > the precise source is, not that it is increasing > and doing so quite rapidly. > > By the way, you said something at the beginning about reducing the CO2 > GWP – but by definition, CO2’s GWP > is always one, as perfect a numerical translation of monotheism as one > could create, I guess..... > > Cheers, Nathan > > Methane at Barrow, Alaska on 9/11/10 > > BRW 2010 09 11 05 1909.11 6.13 .C. > BRW 2010 09 11 06 1937.95 11.47 .C. > BRW 2010 09 11 07 1952.57 5.80 .C. > BRW 2010 09 11 08 1957.61 6.80 .C. > BRW 2010 09 11 09 1935.10 4.13 .C. > BRW 2010 09 11 10 1946.28 7.73 .C. > BRW 2010 09 11 11 1976.60 7.42 .C. > BRW 2010 09 11 12 1982.51 5.45 .C. > BRW 2010 09 11 13 1989.94 3.03 .C. > BRW 2010 09 11 14 1995.60 4.68 .C. > BRW 2010 09 11 15 2009.41 3.65 .C. > BRW 2010 09 11 16 2016.25 5.74 .C. > BRW 2010 09 11 17 2039.49 8.05 .C. > BRW 2010 09 11 18 2046.90 10.47 .C. > BRW 2010 09 11 19 2039.67 3.53 .C. > BRW 2010 09 11 20 2042.08 5.24 .C. > BRW 2010 09 11 21 2058.38 7.64 .C. > BRW 2010 09 11 22 2073.26 2.98 .C. > BRW 2010 09 11 23 2074.07 21.03 .C. > BRW 2010 09 12 00 2067.34 13.10 .C. > BRW 2010 09 12 01 2005.53 1.39 .C. > BRW 2010 09 12 02 1988.98 12.67 .C. > BRW 2010 09 12 03 1965.76 4.13 .C. > BRW 2010 09 12 04 1984.17 10.82 .C. > BRW 2010 09 12 05 1956.75 4.72 .C. > BRW 2010 09 12 06 1941.76 4.05 .C. > BRW 2010 09 12 07 2051.73 112.21 .C. > BRW 2010 09 12 08 2230.78 30.93 .C. > BRW 2010 09 12 09 2181.13 35.70 .C. > BRW 2010 09 12 10 2087.70 26.63 .C. > BRW 2010 09 12 11 1968.64 30.33 .C. > BRW 2010 09 12 12 1928.62 8.78 .C. > > For comparison, here is the same day on the first year of records > there, 1987 > (note that it is not just lower, but also closer to the global average > at the time): > > BRW 1987 09 11 05 -999.99 -99.99 *.. > BRW 1987 09 11 06 1797.62 7.26 .C. > BRW 1987 09 11 07 -999.99 -99.99 *.. > BRW 1987 09 11 08 1814.18 18.15 .C. > BRW 1987 09 11 09 -999.99 -99.99 *.. > BRW 1987 09 11 10 -999.99 -99.99 *.. > BRW 1987 09 11 11 1802.12 4.90 .C. > BRW 1987 09 11 12 1803.20 8.48 .C. > BRW 1987 09 11 13 1814.01 20.46 .C. > BRW 1987 09 11 14 -999.99 -99.99 *.. > BRW 1987 09 11 15 1772.95 4.86 .C. > BRW 1987 09 11 16 -999.99 -99.99 *.. > BRW 1987 09 11 17 1775.05 2.50 .C. > BRW 1987 09 11 18 -999.99 -99.99 *.. > BRW 1987 09 11 19 1766.73 0.65 .C. > BRW 1987 09 11 20 -999.99 -99.99 *.. > BRW 1987 09 11 21 -999.99 -99.99 *.. > BRW 1987 09 11 22 -999.99 -99.99 *.. > BRW 1987 09 11 23 -999.99 -99.99 *.. > BRW 1987 09 12 00 -999.99 -99.99 *.. > BRW 1987 09 12 01 -999.99 -99.99 *.. > BRW 1987 09 12 02 1768.09 1.55 ... > BRW 1987 09 12 03 -999.99 -99.99 *.. > BRW 1987 09 12 04 -999.99 -99.99 *.. > BRW 1987 09 12 05 1782.46 1.00 ... > BRW 1987 09 12 06 1776.73 1.12 ... > BRW 1987 09 12 07 -999.99 -99.99 *.. > BRW 1987 09 12 08 1822.97 10.56 .C. > BRW 1987 09 12 09 -999.99 -99.99 *.. > BRW 1987 09 12 10 1772.28 11.62 .C. > BRW 1987 09 12 11 -999.99 -99.99 *.. > BRW 1987 09 12 12 1774.90 4.82 .C. > > On Feb 22, 4:23 pm, Robert Chris <r.g.ch...@open.ac.uk> wrote: > > > > > Ken > > > May I have your permission to quote your paragraph 'On the other hand > > the Romans ...' in my PhD thesis. > > > This is about as good an exposition of the challenge of > > intergenerational equity arsing from climate change that I could hope > > to find and perfectly demonstrates the paradox of framing climate > > change as an intergenerational problem. We want to do right by them, > > but who is them, the centennial them or the millennial them? Why do > > we assume that all future generations have the same interests, or if > > we don't, on what basis do we favour one against another? Why do we > > tacitly assume that any future world with dramatically fewer people > > would somehow not be as desirable as one with more or less the same > > number as now? The problem is that interesting as these and many > > related questions are, they don't have easy answers that the whole > > world will buy into as a basis for action. So framing climate change > > as an intergenerational problem introduces a slew of intellectual > > challenges of the same order of complexity as the physical climate > > science itself and create an Everest to climb before action can be > > agreed. How much easier if we forgot about the future and just agreed > > amongst ourselves that the intrinsic indecency of fouling our nest and > > squandering scarce resources is a sufficient reason for immediate > > action. Is that too much to ask? > > > That's a little polemical. Hopefully it won't come out like that in > > the thesis. > > > This thread has gone off in a direction I hadn't anticipated when it > > started. Many thanks to those who have contributed. Don't let me > > stop you if you want to continue. > > > Robert > > > On Feb 22, 4:38 pm, Ken Caldeira <kcalde...@carnegie.stanford.edu> > > wrote: > > > > Both amounts and rates of change are important to estimating climate > > > damage. > > > > If we were turning the Earth into the Cretaceous over millions of years, > > > that is not a problem. If we are doing it in centuries, that is a > > > problem. > > > > So, if we are talking about near-term damage from climate change, the > > > Charney sensitivity is the most relevant factor. > > > > If we are talking about long-term damage from a changed climate, then the > > > Earth System sensitivity becomes relevant. > > > > I don't think God made the Earth with the perfect climate and that any > > > cooling or warming is inherently bad. I do think the Earth is full of > > > stuff > > > that is adapted to the current climate and that climate change is > > > damaging. > > > So, I am more concerned with rates of change than absolute amounts of > > > change. > > > > On the century scale of concern to most policy makers, rates and amounts > > > of > > > change are closely linked. > > > > On the other hand, if the Romans had discovered fossil fuels and had a > > > fossil-fueled industrial revolution, they would have maximized their net > > > present value and we would be here two millennia later with rising seas, > > > acidified oceans, melting ice caps, diminished biodiversity, etc, finding > > > little solace in the fact that they followed the path their economists > > > told > > > them was economically optimal. So, even the period with disruptive > > > climate * > > > change* could last thousands of years and Earth System sensitivity becomes > > > relevant on these time scales. However, once climate change stabilizes at > > > a > > > new level, it is not clear to me that the changed climate itself is in any > > > fundamental sense worse than what we started out with. > > > > From a policy perspective, this distinction between changing climate and a > > > changed climate is of little interest, because the prescription is the > > > same > > > in both cases: *Stop using the atmosphere as a waste dump. > > > * > > > > On Wed, Feb 22, 2012 at 3:30 AM, Robert Chris <r.g.ch...@open.ac.uk> > > > wrote: > > > > Tom > > > > > Thanks for > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
